Python Developer Tooling Handbook – Python Tooling Blog

The inaugural Python Packaging Council election closed today.

Claude Mythos 5 registered a PyPI account and published three malicious package versions.

Python’s packaging ecosystem is getting its first elected governance body: the Python Packaging Council.

Run uv init on 0.12 and the main.py you expected is not there. $ uv init example $ cd example $ uv run example Hello from example!

Upgrade Ruff to 0.16.0 and your next ruff check may flag hundreds of new violations.

Pinning requests==2.32.0 in your lockfile was supposed to keep you safe.

When litellm was compromised in March, the malicious versions sat on PyPI for hours.

ty shipped first-class Pydantic support across its July 2026 releases (0.0.57 through 0.0.61), and Pydantic author Sebastián Ramírez signed off on the work publicly.

Python 3.15, due as a release candidate on August 4, 2026, ships PEP 686 enabled by default.

Tools like Ruff, pre-commit, and httpie sit on a developer’s machine for months.

Someone asked me what the new Python Packaging Council could possibly work on “now that uv has largely standardized packaging.” uv has made installing packages, managing environments, and resolving dependencies fast enough that packaging feels solved.

Pixi shipped pixi-build, a preview feature that lets pixi build packages from source instead of only consuming prebuilt conda packages.

Astral is winding down pyx, its hosted commercial registry, and open-sourcing the GPU index and prebuilt-wheel infrastructure underneath it, with the artifacts free.

Larry Hastings (CPython core developer behind the Gilectomy GIL-removal work) released Blanket 1.0 around his PyCon US 2026 talk, “Conquer multithreaded Python with Blanket”.

On July 26, 2025, PyPI maintainers received phishing emails pointing at pypj.org.

The 2026 Python Packaging Summit ran on Friday, May 15 in Long Beach.

The case for staying on mypy has often been migration cost.

Python 3.14.5 landed on 10 May 2026, pulled the incremental garbage collector that shipped in 3.14.0 through 3.14.4, and put the 3.13 generational collector back.

For most of the past year, the speed conversation around Python type checkers has had one shape: mypy is the slow incumbent, and the fast alternatives (ty, Pyrefly, Zuban) earn their speed by being written in Rust. mypy 2.0, released May 6, 2026, takes a…

PEP 723 plus uv made single-file Python scripts easy to share.

Open any Python codebase that’s been through a few hands and you’ll find the same fossils: a for loop adding items to a set one at a time, a conditional slice that could be removesuffix(), a two-line open()/read() that pathlib handles in one call.

import lightning shows up at the top of millions of PyTorch training scripts.

A thread titled “But really, why use uv?”

Note Update 2026-04-29: An earlier version of this post used a multi-line Liskov-violation panel from rich/_null_file.py as an example of ty catching a real protocol bug.

pip 26.0 closed two of uv’s clearest feature gaps in January: PEP 723 script installs and a datetime-based package filter that mirrors uv’s --exclude-newer.

Astral runs ruff, uv, and ty inside the repos that build them.

PyPI completed its second external security audit today.

Astral published a detailed writeup of how they secure the org that ships uv, Ruff, and ty.

Intel shipped AVX2 in 2013.

uv ranked as the most admired technology in Stack Overflow’s 2025 Developer Survey at 74%.

The Python Packaging Summit returns Friday, May 15, 2026 in Room 201A of the Long Beach Convention Center, running 1:45 to 5:45 PM on the Friday of PyCon US.

Tip Want more on uv?

A developer named Roman Dubrovin published repowise, a tool for generating structured wikis from codebases, as his first PyPI package.

In a recently resurfaced 2012 PyData panel discussion, Fernando Perez, Travis Oliphant, and David Cournapeau sat down with Guido van Rossum to discuss the scientific Python community’s needs.

Sebastián Ramírez, creator of FastAPI, recently announced that all his Python projects now use ty for type checking.

Earlier today, someone published malicious versions of litellm (versions 1.82.7 and 1.82.8) to PyPI.

OpenAI announced today that it will acquire Astral, the company behind uv, Ruff, and ty.

Charlie Marsh (founder of Astral, creator of ruff, uv, and ty) joined Michael Chow and Wes McKinney on The Test Set.

Matthew Honnibal, co-founder of Explosion and creator of spaCy, has published a collection of Claude Code skills for Python development.

Pydantic has released Monty, a minimal Python interpreter written in Rust for safely executing LLM-generated code.

Jarek Potiuk, Apache Airflow PMC member and the project’s top committer, gave a talk at FOSDEM 2026 on how Airflow manages its massive Python monorepo.

Astral has released uvx.sh, a service that generates installation scripts for any Python tool on PyPI.

Dagster’s dignified-python-313 skill guides Claude Code to write Python 3.13 code that matches their project conventions.

Tool creators are building their tools with AI coding assistants.

Andrew Nesbitt’s “How uv got so fast” explains that uv’s speed comes less from Rust and more from eliminating work entirely.

Astral released ty, a Python type checker written in Rust, today.

Large language models possess extensive Python knowledge from training data, yet they consistently struggle with modern tooling practices.

Claude Code supports custom hooks that guide the AI agent toward project-specific workflows.

anaging tool versions across multiple configuration files creates persistent headaches in Python development.

Rob Hand’s comparison of emerging type checkers is the first comprehensive look at three new Rust-based tools: ty (Astral), pyrefly (Meta), and zuban (David Halter).